Almost all cellular phones have a silent (manner) mode for replacing a ring tone or melody with a vibration, etc. in public areas such as in a train. When receiving an incoming call in silent mode, a cellular phone generally activates a vibrator including a vibrating motor or the like to inform the user of the incoming call. Such environment as where a cellular phone is set in silent mode often requires the user to refrain from talking on the phone. Therefore, when receiving a call on a cellular phone in silent mode, the user will answer the call in a low voice, ignore the call or place the call on hold. With the cellular phone in auto-answer mode, a recorded or fixed voice message is sent to a calling terminal.
However, even if the user answers the call in a whisper in an environment that requires the setting of silent mode, he/she may disturb others around him/her. Besides, if the user puts the caller on hold, he/she is not always to retrieve the caller from the hold status shortly afterward, which causes the caller inconvenience. If the user ignores the call or sends a recorded voice message by an automatic answer to the calling terminal, he/she cannot inform the caller of the reason why he/she does not answer the call. Consequently, the caller may repeatedly make a call to the cellular phone in silent mode or feel distrust for the user.
In, for example, Japanese Patent Application laid open No. 2003-274459: Reference 1 (paragraphs 0037 to 0044 and FIG. 39), there has been proposed a cellular phone to solve the aforementioned problems. The cellular phone stores different types of voice messages to let the user select a voice message by a keyboard or the like and sends it as a call response message when the user cannot answer the call. As another example, in Japanese Patent Application laid open No. 2002-354128: Reference 2 (paragraphs 0007 and 0009), there has been proposed a cellular phone capable of sending a text message or an image as well as a voice message as a call response message.
According to Reference 1, however, when the user of the cellular phone cannot answer an incoming call, he/she has to press a function key in the operating section of the phone. With the use of such a user interface, the user must remember associations between respective response messages and function keys. Reference 1 describes that the user presets a response message with respect to each case as a means to reduce the trouble (refer to paragraphs 0064 to 0066). By this means, the user is forced to determine the settings for the function keys in advance, which still causes him/her trouble.
Similarly, according to Reference 2, if the user is to make the cellular phone send a response message according to his/her situation, the user is required to preset response messages or change the settings for them. In other words, the user is forced to determine the settings for the response messages in advance, which also causes him/her trouble.